/*
 * Copyright (c) 2003-2008 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors 
 *   may be used to endorse or promote products derived from this software 
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.jmex.swt.lwjgl;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.concurrent.Semaphore;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.jme.util.GameTaskQueue;
import com.jme.util.GameTaskQueueManager;

/**
 * 
 * 
 * @author Jochen Mader - jochen@pramari.com - Aug 30, 2008
 * 
 */
public class UpdateThread extends Thread {
	/**
	 * Logger for this class.
	 */
	private static final Logger logger = Logger.getLogger(UpdateThread.class
			.getName());
	/**
	 * Shared mutex.
	 */
	private Semaphore mutex;
	/**
	 * Threadsafe list of targets.
	 */
	private ArrayList<LWJGLSWTCanvas> targets;
	/**
	 * Comparator for nextupdate run.
	 */
	private CanvasNextrenderComparator comparator;
	/**
	 * Constructor.
	 * 
	 * @param name name for the thread
	 * @param targetcanvas the target canvas
	 */
	public UpdateThread(String name, Semaphore mutex) {
		super(name);
		this.mutex=mutex;
		targets=new ArrayList<LWJGLSWTCanvas>();
		this.comparator=new CanvasNextrenderComparator();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Thread#run()
	 */
	@Override
	public void run() {
		logger.log(Level.INFO,"UpdateThread started in multi thread mode.");
		while (!Thread.interrupted()) {
			long _currentTime=System.currentTimeMillis();
			try {
				mutex.acquire();
				GameTaskQueueManager.getManager().getQueue(GameTaskQueue.UPDATE)
						.execute();
				for(LWJGLSWTCanvas canvas:targets){
					if(_currentTime>canvas.getNextupdate()){
						canvas.update();
						continue;
					}
					break;
				}
			} catch (InterruptedException e) {
				// propagate interruption
				Thread.currentThread().interrupt();
			} finally {
				mutex.release();
			}
			Collections.sort(targets,comparator);
			try {
				Thread.sleep(5);
			} catch (InterruptedException e) {
				// propagate interruption
				Thread.currentThread().interrupt();
			}
		}
	}

	public void addTarget(LWJGLSWTCanvas target) {
		targets.add(target);
	}

	public void removeTarget(LWJGLSWTCanvas target) {
		targets.remove(target);
	}

	private class CanvasNextrenderComparator implements
			Comparator<LWJGLSWTCanvas> {

		/*
		 * (non-Javadoc)
		 * 
		 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
		 */
		public int compare(LWJGLSWTCanvas o1, LWJGLSWTCanvas o2) {
			if (o1.getNextupdate() > o2.getNextupdate()) {
				return 1;
			}
			if (o1.getNextupdate() < o2.getNextupdate()) {
				return -1;
			}
			return 0;
		}

	}
}
